Commentary on developments in the endless dispute between evolution and creationism.

Monday, April 10, 2006

Presenting Evolution

The last two weeks have been very good ones for evolution. First, there was the discovery of the fossil Tiktaalik. This fossil is so clearly transitional between ancient fish and land-dwelling tetrapods that it is probably destined for a permanent place in the biology textbooks. It is one more in a long line of stinging rebukes to creationist claims about the paucity of transitional forms in the fossil record. Nick Matzke provides this excellent post showing how the creationist textbook Of Pandas and People makes gaps in the fossil record a major part of its case, and specfically cites the gap between ancient fish and amphibians as especially significant.

Then came word that another complex biological system has now yielded to an evolutionary explanation. Ian Musgrave has all the details here.

Evolutionists have been handed two major coups in as many weeks, both of which are receiving signficiant media attention. So how would we capitalize on this bout of good publicity?

Not too well, I'm afraid. Two recent events have left me once again vexed at the inability of some on my side of this issue to present themselves effectively.

The first came on Friday night's installment of the MSNBC show Countdown. This show is unique among cable news chat shows in being vaguely left-leaning. It's regular host, Keith Olbermann, is the only cable news host worth watching. Friday's show featured a segment on Tiktaalik. Also on tap was the claim by one exceptionally ignorant person that a recently publicized photo of a kitten born with only one eye and no nose represented evidence for creationism. Evolution says animals are getting better, but this unfortunate kitty was clearly worse, you see.

And what guest did they get to discuss these issues? Bill Nye! The science guy! I was giddy. Like all sensible people, I'm a big fan of Bill Nye. It's hard to imagine someone who has done more to popularize science in innovative ways. Surely, I thought, Nye will hit it out of the park.

So here we had a segment with a stand-alone, articulate, pro-science guest being interviewed by a sympathetic host (not Olbermann, but his guest host Brian Unger). How often does that happen?

Sadly, Nye didn't hit it out of the park. In fact, for much of the interview I couldn't figure out what he was talking about.

The first minute or so of the intervew was wasted on a discussion of Nye's run-in with some unruly audience members at a recent public presentation. P.Z. Myers discussed the incident here. Nye remarked that he didn't feel like he had been heckled, but it was impossible to discern from the ensuing conversation what actually happened.

Finally they got around to Tiktaalik and that's when this exchange took place.

UNGER: Was this still a fish?

NYE: No. It may have been. But the thing is it's going to be a big deal fossil, like the famous archaeopteryx, the feathered bird. It's going to be, as we look through history in the fossil record, this is going to be a significant discovery, because tiktaalik has some fancy feet. There's the famous archaeopteryx, or one of them yeah, it's where they found—we found feathers on an ancient dinosaur, which is a big deal. A significant thing. It tells you a lot about what happened in history in the history of life on earth. And the same will be of this tiktaalik. It's got some unusual wrist bones and unusual crossover between paws and feet and fins.

UNGER: Bill, I know that men of science love pedestrian observations like the one I'm going to make right now, but it kind of looks like a crocodile to me. Could it be a relative of the crocodile that we just didn't discover until now?

NYE: It certainly could be.

UNGER: Why are we calling it...

NYE: You're on your way to becoming a naturalist. That's right. It looks kind of like a crocodile.

UNGER: I am? That sounds obscene, Bill?

NYE: But if you look closely—it sounds obscene if you were somehow embarrassed about nature.

UNGER: But is it a missing link, because it looks sort of like a crocodile? It takes a .

NYE: Well, the word missing link is charged with connotations that you may not want to carry with. But what it is is it's something that's very fishlike, very land animal-like, but has aspects of both and it was discovered on a remote island in the Arctic. I don't know what you do with your day, but I don't go looking for fossils in the Arctic. There are people who do.

If you were learning about this fossil for the first time from this segment, would you have any idea what Nye was talking about? They're well into the conversation before Nye finally gets around to mentioning that Tiktaalik is transitional between fish and land-dwellers, though even here his explanation is hard to follow. And he never gets around to saying that the fossil was found in rocks of exactly the right age, in exactly the right kind of environment. Meanwhile, he kept talking about Archaeopteryx wihtout ever really saying clearly why that particular fossil was so significant. And he never pointed out that actually this is just one more in a long line of transitional forms.

From here the conversation turned to that deformed kitten. Nye did better here, but it was still difficult to ferret out his main points. Opportunity missed.

How about that excellent paper showing, at an unprecedented level of detail, how a particular complex molecular system evolved? Sadly, the press release from the University of Oregon (where the work in question was done) sounds entirely the wrong note:

Using new techniques for resurrecting ancient genes, scientists have for the first time reconstructed the Darwinian evolution of an apparently “irreducibly complex” molecular system.

The research was led by Joe Thornton, assistant professor of biology at the University of Oregon’s Center for Ecology and Evolutionary Biology, and will be published in the April 7 issue of SCIENCE.

How natural selection can drive the evolution of complex molecular systems—those in which the function of each part depends on its interactions with the other parts—has been an unsolved issue in evolutionary biology. Advocates of Intelligent Design argue that such systems are “irreducibly complex” and thus incompatible with gradual evolution by natural selection.

“Our work demonstrates a fundamental error in the current challenges to Darwinism,” said Thornton. “New techniques allowed us to see how ancient genes and their functions evolved hundreds of millions of years ago. We found that complexity evolved piecemeal through a process of Molecular Exploitation—old genes, constrained by selection for entirely different functions, have been recruited by evolution to participate in new interactions and new functions.”

Oh, brother. The fundamental error(s) in current challenges to Darwinism have been laid bare for about a decade now. Behe's “irreducible complexity” argument was a total nonstarter. It was faulty as a matter of logic, since it is a triviality to imagine scenarios whereby known evolutionary mechanisms lead to IC systems. And it was wrong biologically, since there are quite a few complex biological systems whose evolution has been unravelled.

Yet here comes these fellows from the University of Oregon to tell people that Behe used to have a good point, but not any more because of this new work. I don't think that was their intention, but that was the message this silly press release sent.

In his Commentary (I'm not sure if a subscription is required to read this) for Science magazine on this subject, Christoph Adami did a better, though still inadequate, job of putting things in perspective. Here's his closing paragraph:

The Bridgham et al. and Lenski et al. (4) studies are of particular scientific interest, given the political attention given to intelligent design lately. Although these authors have not directly addressed this controversy in the discussion of their work--because the work itself is intrinsically interesting to biologists--such studies solidly refute all parts of the intelligent design argument. Those “alternate” ideas, unlike the hypotheses investigated in these papers, remain thoroughly untested. Consequently, whatever debate remains must be characterized as purely political.

It's good that Adami makes it clear that this work was not motivated by anything the ID folks are saying. The proper way to present this story is to state the results obtained, that the evolution of a complex molecular system has been explained at an impressive level of detail, and add as an afterthought that this puts yet another nail in the ID coffin.

But why oh why is Adami saying that ID ideas have not been thoroughly tested? They have been, at great length, and have been shown to range from false to worthless. Behe's arguments were wrong on the day he first made them, a fact that was obvious to anyone who knew a little biology and could think clearly for a few minutes. Dembski's arguments were vague and worthless from the day he introduced them. Likewise for every other ID proponent.

And Adami's article appears under the headline “Reducible Complexity,” thereby repeating the error from the U of O press release.

4 Comments:

One more bit of good news for evolution: 2 bills in the Maryland General Assembly that would have favored teaching Intelligent Design Creationism have failed ( see here). One bill would have prohibited ID to be taught in science class but allowed it to be taught in humanities or philosophy classes (as if it were scientifically valid). The other bill would have granted "Academic Freedom" to allow (specifically including) ID to be taught.